Re: DatabaseMetaData.getTypeInfo() - returns all tables as well

From: Thomas Kellerer <spam_eater(at)gmx(dot)net>
To: pgsql-jdbc(at)postgresql(dot)org
Subject: Re: DatabaseMetaData.getTypeInfo() - returns all tables as well
Date: 2015-10-20 06:07:31
Message-ID: n04lmu$pk6$1@ger.gmane.org
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No particular problem besides performance.

But I'm surprised: why would this break anything?
Why does the driver rely on tables from pg_catalog be returned for type information?

Thomas

Dave Cramer schrieb am 19.10.2015 um 17:33:
> This change breaks more than it fixes!
>
> What is your specific problem with returning tables ?
>
> Dave Cramer
>
> davec(at)postgresintl(dot)com <mailto:davec(at)postgresintl(dot)com>
> www.postgresintl.com <http://www.postgresintl.com>
>
> On 1 October 2015 at 08:51, Thomas Kellerer <spam_eater(at)gmx(dot)net <mailto:spam_eater(at)gmx(dot)net>> wrote:
>
> Sorry, I am not registered with GitHub (nor using it)
>
> Regards
> Thomas
>
> Dave Cramer schrieb am 01.10.2015 um 13:23:
> > Hi Thomas,
> >
> > Any chance you could provide a github pull request ?
> >
> > Dave Cramer
> >
> > dave.cramer(at)credativ(dot)ca
> > http://www.credativ.ca
> >
> > On 30 September 2015 at 15:37, Thomas Kellerer <spam_eater(at)gmx(dot)net <mailto:spam_eater(at)gmx(dot)net> <mailto:spam_eater(at)gmx(dot)net <mailto:spam_eater(at)gmx(dot)net>>> wrote:
> >
> > Hello,
> >
> > DatabaseMetaData.getTypeInfo() returns not only data types, but also all table types.
> >
> > Strictly speaking this is correct as the row type for a table is indeed a "data type" in Postgres,
> > but I think the information returned is way too much from a practical point of view.
> >
> > This could be reduced at least a bit by not only excluding pg_toast, but also pg_catalog and information_schema types:
> >
> > SELECT t.typname,t.oid
> > FROM pg_catalog.pg_type t
> > JOIN pg_catalog.pg_namespace n ON (t.typnamespace = n.oid)
> > WHERE n.nspname not in ('pg_toast', 'pg_catalog', 'information_schema')
> >
> > (instead of WHERE n.nspname != 'pg_toast' in AbstractJdbc2DatabaseMetaData.java getTypeInfo())
> >
> >
> > What I find even more confusing (from a JDBC point of view) is that each table type is reported twice:
> >
> > Once with the table's name and once with an underscore prefixing the table name, e.g. foo and _foo.
> >
> > These entries map to pg_type rows with typtype = 'c' and 'b' respectively.
> >
> > I wonder if it would make sense to filter out the "real" tables from this result.
> > And if it does, if there is an efficient way of doing that and not removing real composite types
> > from the result at the same time.
> >
> >
> > Regards
> > Thomas
> >
> >
> >
> >
> > --
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>
>
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